Interesting article on food of primates/hunter gatherers and the diversity htat it can encompass. You really have to read the whole article for it to make sense. From largely plant based to largely animal based as long as it isn't processed you are on the right track.
While it's true humans are related to all other primates, and most closely to the apes, there are some significant differences.
It's important to look at the large events in human evolution, particularly those since speciation from chimps, which are our closest relatives, starting with the last common ancestor we share with chimps. This last common ancestor existed approximately 5-8 million years ago. This coincided with the formation of the Great Rift Valley of eastern Africa, and the concurrent development of savannas and grassland (as opposed to coast-to-coast forests which preceded this landscape).
For the majority of human evolution (the entire period of australopithecus, which preceded the homo genus) up to the proliferation of homo erectus (stretching from 5-8M years ago to about 1.8M years ago) human ancestors lived in this grassland area no wider than a single time zone, while our ape relatives remained in forested areas. During this several million year period, we were under very different evolutionary pressures than our ape relatives (which lived in an environment essentially unchanged from that which they evolved in).
Specifically, a savanna environment (like any grassland) is not conducive to a primarily vegetarian diet except for ruminants and other grazing animals.
This pressure is what likely pushed our ancestors to begin scavenging and eventually hunting to provide food.
So, while we share origins with apes and other primates, we evolved away from them in a very different environment, and should realize that the best species to compare against for humans would be other primates that have evolved on a grassland environment.
I do agree with the quality of food points in the article; I just question the author's choice to compare directly to the majority of primates which have remained in a forest (usually tropical or near-tropical) environment.
Greg B- So would Baboons be a vaugely analogous primate to look at in terms of similarities to very early humans?
Yes. I'm still in the process of researching the topic (in addition to a class I'm taking on evolutionary economics that covers some similar topics, albeit from a different viewpoint), so I can't talk much about baboons yet, but they are the best place to look for analogs to human features.
And analogous features are what we look for, as opposed to homologous features. Analogous features share a similarity in function regardless of structure (indicating evolutionary pressure caused the change) and homologous features share a similarity in structure, regardless of function (indicating common origin rather than evolutionary pressure). An example would be a bat wing, which is homologous to any other mammalian fore-leg, but analogous to a bird's wing.